ECSS Paris 2023: CP-PN05
INTRODUCTION: New Zealand Blackcurrants (NZBC) have been well described as ergogenic aids. It has been postulated that the NZBC related performance effects could be the result of a better oxygen delivery to the muscles, which in turn could lead to an improved running economy (RE) and substrate utilisation. We aimed to investigate the effects of 7-day NZBC supplementation on 5km running performance, running economy and substrate utilisation in trained male and female runners. METHODS: 9 males (31.8±10.3y, BMI:23.4±2.3 kg/m2, VO2max:52.1±6.5 mL/kg/min) and 9 females (31.2±9.5y, BMI:21.8±2.1 kg/m2, VO2max:47.2±5.8 mL/kg/min) were recruited. Using a double-blind, randomised, placebo controlled, cross-over design, participants received 600 mg/day NZBC extract (containing 210 mg anthocyanins) or a placebo (PLA) for 7 days prior to assessing RE and metabolic responses at 75%, 85% and 95% of LT2 followed by a 5km time trial (TT). RE and metabolic parameters were determined via breath-by-breath analysis and TT performance by completion time. RESULTS: The 5km TT was completed in 1355±147s and 1191±100s for females and males resp. in PLA. NZBC supplementation did not have significant effects on TT performance in males (1215±118s, P=0.2). In the female group there was a strong trend toward improved TT performance with a completion time of 1335±158s (P=0.051). RE was lower at the higher (95% and 85%LT2) intensities compared to 75%LT2 at a group level for both PLA (184.0±12.61, 188.3±14.13 and 198.0±17.02 mL/kg/km, resp. P<0.05) and NZBC (180.1±14.56, 181.1±15.82 and 190.2±15.52 mL/kg/km, resp. P<0.05). No significant differences were found in RE between trials at group level for females and males at the different intensities (P>0.05). NZBC did not alter total energy expenditure at 75%, 85% or 95%LT2 when compared to PLA at a group (11.2±2.31, 12.7±3.04, 14.2±3.54 kcal/min vs. 11.9±2.44, 13.3±2.77, 14.9±3.21kcal/min resp. (P>0.1) or gender specific level. Carbohydrate and fat oxidation also did not differ between PLA and NZBC (P>0.1). CONCLUSION: 7 Days of New Zealand Blackcurrant supplementation did not significantly improve running economy, performance or substrate use in trained runners but there was a strong trend towards improved performance for female athletes. These results underline the differences between male and female physiology and the need for more gender specific research.
Read CV Ralph MandersECSS Paris 2023: CP-PN05
INTRODUCTION: Accumulating evidence suggests that each person has an immensely diverse and stable gut microbiota whose composition influences the health of the host through their metabolites. Diet and nutritional status are key factors in determining gut microbiota composition and their metabolites. Medium-chain triglycerides (MCTs), which are more quickly metabolized than long-chain triglycerides (LCTs) in the body, are widely known to lose body mass and fat mass. Recent studies have reported that MCTs-enriched diets could affect gut microbiota composition and gut health in obese individuals［1］. However, it remains unclear whether the intake of MCTs exerts a beneficial effect on gut health in athletes as well. Therefore, the purpose of the present study was to investigate the effects of MCTs supplementation on gut microbiota composition and gut health in female university football players. METHODS: Seventeen female university footballers were enrolled and randomly assigned to receive either MCTs (MCT group, n = 9) or Rapeseed oil (LCT group, n = 8). They consumed jelly sticks containing 18 g MCTs or LCTs every day for 6 weeks. We evaluated energy intake, energy expenditure, body composition, gut microbiota and its metabolite before and at the end of the intervention. In addition, self-reported bowel movement frequency was surveyed. RESULTS: Energy intake and energy expenditure before and during the 6-week intervention did not differ between both groups. In the MCT group, the percentage of total body fat after the intervention was significantly lower than before the intervention (p = 0.03), whereas no significant change was observed in the LCT group. A significant decrease in Firmicutes/Bacteroidetes ratio, which is known to have an important role in maintaining normal intestinal homeostasis, was observed in the MCT group (p < 0.05), but not in the LCT group. In addition, the total fecal short-chain fatty acid concentration, which is reported to stimulate colonic motility and accelerate colonic transit, significantly increased in the MCT group (p < 0.05), while such effect was not observed in the LCT group. Self-reported bowel movement frequency was significantly increased after the intervention in the MCT group, but not in the LCT group (p < 0.01). CONCLUSION: Six-week intake of MCTs supplementation may cause changes in the composition of gut microbiota and their metabolites, leading to improved bowel movements in female university football players. REFERENCE: 1. Rial SA. et al. Gut microbiota and metabolic health: the potential beneficial effects of a medium chain triglyceride diet in obese individuals. Nutrients, 2016. 8(5): 281.
Read CV Aya IshibashiECSS Paris 2023: CP-PN05
INTRODUCTION: The aim of the study was to investigate effects of 12 wk training with post-exercise protein supplementation on body composition in untrained, healthy females. METHODS: Participants (n = 27, 33.1 ± 9.2 y, mass 69.5 ± 13 kg, BMI < 30, VO2max 27.3 + 3.7 ml/kg/min) undertook upper-body resistance training (2 x/wk) and HIIT cycling (3 x/wk). Participants were told this is not a weight loss programme and they should adjust dietary intakes to maintain weight.Dietary intakes (3-day record) were measured at wk 0,4,8,12, body composition (DXA) at wk 0 and 12. Participants consumed either a high- (24 g, N = 15 ,P) or equicaloric low- (3 g, N = 12, C) protein post-exercise supplement (510 kJ). RESULTS: Average daily intakes of total energy wk 4-12 in P and C (7.2 ± 1.1 , 7.9 ± 1.1 MJ, resp. P = 0.17 ) and protein (90 ± 14 , 85 ± 12 g., resp. P = 0.28 ) were similar. There was little change in body mass with training (P =0.56) and no significant difference between P and C (Δ 0.04 ± 2.2 kg, 0.38 ± 1.3, resp. P=0.64). There was a large variability in change in fat mass such that the change over time was not significant (P = 0.12). There was no difference between P and C (Δ -0.5 ± 1.9 , - 0.5 ± 1.2 kg, resp. P = 0.98). Participants gained lean mass (P = 0.008) but there was no difference between P and C (Δ 0.6 ± 1.4 , 0.8 ± 0.8 kg, resp. P = 0.56). CONCLUSION: Post-exercise protein supplementation (24 g) appears not to impact body composition changes in normal weight, healthy, untrained women who undergo 12 wk of mixed aerobic and resistance training. The fact that total dietary intakes of protein did not differ between groups and that protein was likely in excess of needs (~1.2 g/kg) likely account for the lack of effect of protein supplementation on body composition.
Read CV Nancy RehrerECSS Paris 2023: CP-PN05